[Coco] Ideas for a Graphics Project, part 2

Roger Taylor roger at newfoal.com
Tue Oct 25 20:19:36 EDT 2005


At 03:28 PM 10/25/2005, you wrote:
>Not exactly the same. If you look at the memory map for a Coco3, you will 
>see a single MMU block $60000-$67FFF for high resolution graphics. There 
>is no highres equivalent to PMODEn,m where m can be changed.
>
>If you have more memory than 128K on a Coco3, then you can make use of any 
>memory below $68000 for high resolution graphics. You can manipulate the 
>system to swap blocks and get similar effects to the BALL program.
>
>Roger Taylor's Projector series of programs swaps three highres graphic 
>screens to increase the number of on-screen colors into the thousands. 
>John Kowalski (Sockmaster) does something similar (HiColor) with two screens.
>
>There probably are other examples but I can't think of them offhand.
>
>Robert Emery wrote:
>>Excellent info, thanks Robert. Are there any similar programs for the CoCo3?
>>Seems like they all rely on palette cycling, but it should be possible to set
>>up a few graphic pages on a 512K machine and flip through them, possibly
>>cycling the palette at the same time for some advanced looking animation.
>>Bob


To answer Bob's question and to comment on Robert:

Sockmaster's Hi-Color mode as in Twilight Terminal is superior to The 
Projector's and Projector-3's flicker modes.  Sock's Hi-Color mode is 
complex enough to boggle you for hours.  In fact, I never learned just how 
he does it even after many attempts of him explaining it to me... and I am 
a super fast learner.  However, it involves two screens each filtered for a 
different color and palette set to achieve even more colors and less 
flicker than what P-3 can do.

P-3 cycles through three screens at 60hz, each filtered using red, green, 
and blue.  The more gray shades you can make for each screen, the less 
flicker.  So each screen in P-3 simulates 13 levels of red, green, or blue 
for a ~13x13x13 color mode.

I encourage anybody interested to get with Sockmaster and bug him until you 
fully understand his Hi-Color mode and then try to apply it to new graphics 
software.  Just keep in mind that his mode is very demanding on the CPU and 
it may not be ideal for most applications.  P-3 cycles through it's screens 
and palettes in the background using the 60hz IRQ, so there is no 
noticeable load.


-- 
Roger Taylor



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